scholarly journals Cardioprotective Effects of Voluntary Exercise in a Rat Model: Role of Matrix Metalloproteinase-2

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Anikó Pósa ◽  
Renáta Szabó ◽  
Krisztina Kupai ◽  
Zoltán Baráth ◽  
Zita Szalai ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Infarct Size ◽  
Voluntary Exercise ◽  
Matrix Metalloproteinase 2 ◽  
Moderate Intensity ◽  
Protective Mechanism ◽  
Ring Contraction ◽  
Aorta Ring ◽  
Heart Perfusion ◽  
Basal Blood Pressure

Background. Regular exercise at moderate intensity reduces cardiovascular risks. Matrix metalloproteinases (MMPs) play a major role in cardiac remodeling, facilitating physiological adaptation to exercise. The aim of this study was to examine the influence of voluntary physical exercise on the MMP-2 enzyme activity and to investigate the cardiac performance by measurement of angina susceptibility of the heart, the basal blood pressure, the surviving aorta ring contraction, and the cardiac infarct size after I/R-induced injury.Methods. Male Wistar rats were divided into control and exercising groups. After a 6-week period, the serum level of MMP-2, basal blood pressure, cardiac angina susceptibility (the ST segment depression provoked by epinephrine and 30 s later phentolamine), AVP-induced heart perfusion and aorta ring contraction, infarct size following 30 min ischemia and 120 min reperfusion, and coronary effluent MMP-2 activity were measured.Results. Voluntary wheel-running exercise decreased both the sera (64 kDa and 72 kDa) and the coronary effluent (64 kDa) MMP-2 level, reduced the development of ST depression, improved the isolated heart perfusion, and decreased the ratio of infarct size.Conclusion. 6 weeks of voluntary exercise training preserved the heart against cardiac injury. This protective mechanism might be associated with the decreased activity of MMP-2.

scholarly journals Sexual Dimorphism of Cardiovascular Ischemia Susceptibility Is Mediated by Heme Oxygenase

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Anikó Pósa ◽  
Krisztina Kupai ◽  
Rudolf Ménesi ◽  
Zita Szalai ◽  
Renáta Szabó ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sexual Dimorphism ◽  
Heme Oxygenase ◽  
Blood Pressure Response ◽  
Isolated Heart ◽  
Reproductive Age ◽  
Female Rat ◽  
Heart Perfusion ◽  
Basal Blood Pressure

We investigated the gender differences in heme-oxygenase (HO) enzyme, which produces endogenous vascular protective carbon monoxide (CO). We studied (1) the activity and expression of HO enzymes in the left ventricle (LV) and aorta, (2) basal increase in basal blood pressure provoked by arginine vasopressine (AVP)in vivo, (3) the heart perfusion induced by AVP, (4) the ST segment depression provoked by adrenaline and 30 seconds later phentolamine, and (5) the aorta ring contraction induced by AVP in female and male Wistar rats. We found that HO activity and the expression of HO-1 and HO-2 were increased in female rat aorta and LV. We demonstrated that the basal blood pressure and administration of AVP provoked blood pressure response are increased in the males; the female myocardium was less sensitive towards angina. Both differences could be aggravated by the inhibition of HO. The aorta rings were more susceptible towards vasoconstriction by AVP in males; isolated heart perfusion decrease was higher in males. The HO inhibition aggravated the heart perfusion in both sexes. In conclusion, the increased HO activity and expression in females might play a role in the sexual dimorphism of cardiovascular ischemia susceptibility during the reproductive age.

scholarly journals Carbohydrate Restriction with or without Exercise Training Improves Blood Pressure and Insulin Sensitivity in Overweight Women

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 637
Author(s):  
Shengyan Sun ◽  
Zhaowei Kong ◽  
Qingde Shi ◽  
Haifeng Zhang ◽  
On-Kei Lei ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Fasting Glucose ◽  
Training Group ◽  
Moderate Intensity ◽  
Cardiometabolic Health ◽  
Carbohydrate Restriction ◽  
Obese Women ◽  
Low Carbohydrate Diet

Objective: The purpose of this study was to evaluate the effects of a 4-week low-carbohydrate diet (LC) with or without exercise training on cardiometabolic health-related profiles in overweight/obese women. Methods: Fifty overweight/obese Chinese women (age: 22.2 ± 3.3 years, body mass index (BMI): 25.1 ± 3.1 kg·m−2) were randomized to either a LC control group (LC-CON, n = 16), a LC and high-intensity interval training group (LC-HIIT, n = 17), or a LC and moderate-intensity continuous training group (LC-MICT, n = 17). All groups consumed LC for 4 weeks, while the LC-HIIT and LC-MICT groups followed an additional five sessions of HIIT (10 × 6 s cycling sprints and 9 s rest intervals, 2.5 min in total) or MICT (cycling continuously at 50–60% of peak oxygen uptake (VO2peak) for 30 min) weekly. Blood pressure, fasting glucose, insulin sensitivity, and several metabolic or appetite regulating hormones were measured before and after intervention. Results: Significant reductions in body weight (− ~2.5 kg, p < 0.001, η2 = 0.772) and BMI (− ~1 unit, p < 0.001, η2 = 0.782) were found in all groups. Systolic blood pressure was reduced by 5–6 mmHg (p < 0.001, η2 = 0.370); fasting insulin, leptin, and ghrelin levels were also significantly decreased (p < 0.05), while insulin sensitivity was improved. However, there were no significant changes in fasting glucose, glucagon, and gastric inhibitory peptide levels. Furthermore, no group differences were found among the three groups, suggesting that extra training (i.e., LC-HIIT and LC-MICT) failed to trigger additional effects on these cardiometabolic profiles. Conclusions: The short-term carbohydrate restriction diet caused significant weight loss and improved blood pressure and insulin sensitivity in the overweight/obese women, although the combination with exercise training had no additional benefits on the examined cardiometabolic profiles. Moreover, the long-term safety and effectiveness of LC needs further study.

Physical exercise and blood pressure with reference to the angiotensinogen M235T polymorphism

2002 ◽  
Vol 10 (2) ◽  
pp. 71-77 ◽  
Author(s):  
Rainer Rauramaa ◽  
Raimo Kuhanen ◽  
Timo A. Lakka ◽  
Sari B. Väisänen ◽  
Pirjo Halonen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Reference Group ◽  
Controlled Trial ◽  
Exercise Group ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Blood Pressures ◽  
Agt Gene ◽  
M235t Polymorphism

We investigated the role of the angiotensinogen (AGT) gene M235T polymorphism in determining blood pressure (BP) response to moderate intensity exercise in a 6-yr randomized controlled trial in 140 middle-aged men. Sitting, supine, and standing blood pressures were measured annually. Of the randomized men, 86% participated in the trial for 6 yr. Submaximal cardiorespiratory fitness increased by 16% in the exercise group. In the M homozygotes, sitting systolic BP decreased by 1.0 mmHg in the exercise but increased by 14.6 mmHg in the reference group ( P = 0.007 for net effect). Sitting and supine diastolic BP decreased by 6.2 and 3.3 mmHg in the exercise but increased by 2.8 and 3.2 mmHg in the reference group ( P = 0.026 and 0.024 for net effects), respectively. Regular moderate intensity exercise attenuates aging-related increase in systolic BP and decreases diastolic BP among the M homozygotes of the AGT gene M235T polymorphism.

Contribution of Vascular Nitric Oxide to Basal Blood Pressure in Conscious Spontaneously Hypertensive Rats and Normotensive Wistar Kyoto Rats

1995 ◽  
Vol 89 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Naoyoshi Minami ◽  
Yutaka Imai ◽  
Jun-Ichiro Hashimoto ◽  
Keishi Abe
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Methyl Ester ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto Rats ◽  
Basal Blood Pressure ◽  
Wistar Kyoto

1. The aim of this study was to clarify the extent to which vascular nitric oxide contributes to basal blood pressure in conscious spontaneously hypertensive rats and normotensive Wistar Kyoto rats. 2. The contribution of vascular nitric oxide to maintenance of blood pressure was estimated by measuring the pressor response to an intravenous injection of nitric oxide synthase inhibitor, Nω-l-arginine methyl ester, given after serial injections of captopril, vasopressin V1-receptor antagonist (V1-antagonist) and ganglion blocker (pentolinium) in conscious spontaneously hypertensive and Wistar Kyoto rats aged 20–28 weeks. To estimate the ‘amplifier property’ of hypertrophied vasculature in spontaneously hypertensive rats, which is known to modulate pressor responses, the lower blood pressure plateau after serial injections of captopril, V1-antagonist and pentolinium and the maximum blood pressure elicited by subsequent injection of increasing doses of phenylephrine were also measured. 3. The serial injections of captopril, V1-antagonist and pentolinium decreased mean arterial pressure from 164 ± 9 mmHg to 67 ± 2 mmHg and from 117 ± 2 mmHg to 49 ± 1 mmHg in spontaneously hypertensive and Wistar Kyoto rats respectively. The subsequent injection of Nω-l-arginine methyl ester restored mean arterial pressure almost to its control levels in both spontaneously hypertensive and Wistar Kyoto rats. The absolute changes in mean arterial pressure elicited by Nω-l-arginine methyl ester were significantly greater in spontaneously hypertensive than in Wistar Kyoto rats (P < 0.01), but there was no significant difference in the responses to Nω-l-arginine methyl ester when they were expressed as percentages of either the lower blood pressure plateau or maximum blood pressure. 4. These results indicate that basal blood pressure in both spontaneous hypertensive and Wistar Kyoto rats is maintained by a balance between vascular nitric oxide and major pressor systems. They also suggest that the vasodilatory effect of vascular nitric oxide does not differ between spontaneously hypertensive and Wistar Kyoto rats, and that the increased pressor effect of Nω-l-arginine methyl ester in spontaneously hypertensive rats is due to a vascular amplifier mechanism.

Blood pressure regulation by ETA and ETB receptors in conscious, telemetry-instrumented mice and role of ETA in hypertension produced by selective ETB blockade

2006 ◽  
Vol 290 (6) ◽  
pp. H2554-H2559 ◽  
Author(s):  
Ryan M. Fryer ◽  
Pamela A. Rakestraw ◽  
Patricia N. Banfor ◽  
Bryan F. Cox ◽  
Terry J. Opgenorth ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Pressure Regulation ◽  
Pressure Regulation ◽  
Type B ◽  
Selective Antagonist ◽  
Relevant Role ◽  
Basal Blood Pressure ◽  
Baseline Values

The net contribution of endothelin type A (ETA) and type B (ETB) receptors in blood pressure regulation in humans and experimental animals, including the conscious mouse, remains undefined. Thus we assessed the role of ETA and ETB receptors in the control of basal blood pressure and also the role of ETA receptors in maintaining the hypertensive effects of systemic ETB blockade in telemetry-instrumented mice. Mean arterial pressure (MAP) and heart rate were recorded continuously from the carotid artery and daily (24 h) values determined. At baseline, MAP ranged from 99 ± 1 to 101 ± 1 mmHg and heart rate ranged between 547 ± 15 and 567 ± 19 beats/min ( n = 6). Daily oral administration of the ETB selective antagonist A-192621 [10 mg/kg twice daily] increased MAP to 108 ± 1 and 112 ± 2 mmHg on days 1 and 5, respectively. Subsequent coadministration of the ETA selective antagonist atrasentan (5 mg/kg twice daily) in conjunction with A-192621 (10 mg/kg twice daily) decreased MAP to baseline values on day 6 (99 ± 2 mmHg) and to below baseline on day 8 (89 ± 3 mmHg). In a separate group of mice ( n = 6) in which the treatment was reversed, systemic blockade of ETB receptors produced no hypertension in animals pretreated with atrasentan, underscoring the importance of ETA receptors to maintain the hypertension produced by ETB blockade. In a third group of mice ( n = 10), ETA blockade alone (atrasentan; 5 mg/kg twice daily) produced an immediate and sustained decrease in MAP to values below baseline (baseline values = 101 ± 2 to 103 ± 2 mmHg; atrasentan decreased pressure to 95 ± 2 mmHg). Thus these data suggest that ETA and ETB receptors play a physiologically relevant role in the regulation of basal blood pressure in normal, conscious mice. Furthermore, systemic ETB receptor blockade produces sustained hypertension in conscious telemetry-instrumented mice that is absent in mice pretreated with an ETA antagonist, suggesting that ETA receptors maintain the hypertension produced by ETB blockade.

scholarly journals Modeling of Metabolic Equivalents (METs) during Moderate Resistance Training Exercises

2021 ◽  
Vol 11 (18) ◽  
pp. 8773
Author(s):  
Muhammad Adeel ◽  
Chien-Hung Lai ◽  
Chun-Wei Wu ◽  
Jiunn-Horng Kang ◽  
Jian-Chiun Liou ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Resistance Training ◽  
Perceived Exertion ◽  
Training Group ◽  
Repeated Measure ◽  
Moderate Intensity ◽  
Measure Data ◽  
Training Experience ◽  
Metabolic Equivalents ◽  
Resting Period

Energy expenditure through metabolic equivalent (MET) prediction during resistance exercises in humans can be modeled by using cardiorespiratory parameters. In this study, we aimed to predict MET during six moderate-intensity resistance training sessions consisting of three different exercises. Eleven participants were recruited into two groups; an untrained (n = 5; with no resistance training experience) and a trained group (n = 6; with 2 months resistance training experience). Each participant completed six training sessions separated with a rest interval of 1–2 days. While wearing a mask for indirect calorimetric measurements using Cortex Metalyzer 3B, each participant performed training sessions consisting of three types of dumbbell exercises: shoulder press, deadlift, and squat. The metabolic equivalents (METs), respiratory exchange ratio (RER), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), blood lactate (BL), and Borg rate of perceived exertion (RPE) were measured. The MET was predicted using generalized estimating equations (GEE) for repeated measure data collected during exercise and rest periods. It was observed that during exercise period, RER, HR, SBP, and BL for the training group (QIC = 187, 95% CI = −0.012~0.915, p = 0.000*~0.033*) while RER, HR, SBP, DBP, and RPE (QIC = 48, 95% CI = −0.024~0.422, p = 0.000*~0.002*) during resting period for untrained group significantly predicted MET for moderate-intensity interval resistance training. It is concluded that the cardiorespiratory variables are significantly related to MET. During exercise, RER and HR significantly predicted MET for both groups along with additional parameters of SBP and BL for the training group. While during the resting period, RER, HR, SBP, DBP, and RPE related significantly for untrained and BL for training group respectively.

ACE gene and physical activity, blood pressure, and hypertension: a population study in Finland

2002 ◽  
Vol 92 (6) ◽  
pp. 2508-2512 ◽  
Author(s):  
Ricardo M. Fuentes ◽  
Markus Perola ◽  
Aulikki Nissinen ◽  
Jaakko Tuomilehto
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Leisure Time Physical Activity ◽  
Population Based ◽  
Moderate Intensity ◽  
P Value ◽  
Arterial Blood ◽  
Main Effect ◽  
History Of ◽  
Middle Aged Adults

The study evaluated the association of the insertion/deletion polymorphism of the angiotensin-converting enzyme gene (ACE I/D) with self-reported moderate-intensity leisure time physical activity (MILTPA), arterial blood pressure (BP) and history of hypertension (HT). A representative population-based sample of 721 middle-aged adults (358 women) from two areas of Finland was genotyped for the ACE I/D. After exclusion criteria were applied, 455 subjects (288 women) were selected for the analysis. The distribution of the ACE I/D genotypes did not differ significantly among frequent vs. nonfrequent MILTPA groups (χ2 = 2.556; df = 2; P value = 0.279). The main predictors of BP were male gender, age, body mass index, and arterial pulse. Additionally, tobacco smoking and alcohol consumption also had a significant main effect on diastolic BP. HT was significantly more frequent in subjects with obesity, family history of cardiovascular disease, or lower educational level. As for BP, neither ACE I/D nor MILTPA was associated with HT. The study confirmed recent reports from population-based studies of no association between ACE I/D and physical fitness. The study also confirmed a lack of association between ACE I/D and BP or HT.

scholarly journals Role of myosin light chain kinase in regulation of basal blood pressure and maintenance of salt-induced hypertension

2011 ◽  
Vol 301 (2) ◽  
pp. H584-H591 ◽  
Author(s):  
Wei-Qi He ◽  
Yan-Ning Qiao ◽  
Cheng-Hai Zhang ◽  
Ya-Jing Peng ◽  
Chen Chen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Vascular Tone ◽  
Induced Hypertension ◽  
Basal Blood Pressure ◽  
Muscle Myosin

Vascular tone, an important determinant of systemic vascular resistance and thus blood pressure, is affected by vascular smooth muscle (VSM) contraction. Key signaling pathways for VSM contraction converge on phosphorylation of the regulatory light chain (RLC) of smooth muscle myosin. This phosphorylation is mediated by Ca2+/calmodulin-dependent myosin light chain kinase (MLCK) but Ca2+-independent kinases may also contribute, particularly in sustained contractions. Signaling through MLCK has been indirectly implicated in maintenance of basal blood pressure, whereas signaling through RhoA has been implicated in salt-induced hypertension. In this report, we analyzed mice with smooth muscle-specific knockout of MLCK. Mesenteric artery segments isolated from smooth muscle-specific MLCK knockout mice (MLCKSMKO) had a significantly reduced contractile response to KCl and vasoconstrictors. The kinase knockout also markedly reduced RLC phosphorylation and developed force. We suggest that MLCK and its phosphorylation of RLC are required for tonic VSM contraction. MLCKSMKO mice exhibit significantly lower basal blood pressure and weaker responses to vasopressors. The elevated blood pressure in salt-induced hypertension is reduced below normotensive levels after MLCK attenuation. These results suggest that MLCK is necessary for both physiological and pathological blood pressure. MLCKSMKO mice may be a useful model of vascular failure and hypotension.

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